These studies are designed to explore the reciprocal effects of cytomegalovirus (CMV) and pregnancy in an adolescent population and to define the impact of this virus infection upon the offspring of these youthful mothers. Preliminary results have demonstrated an unusually high prevalance of CMV infections among pregnant adolescents and their offspring. These results, as yet unexplained, may reflect specific age-associated risk factors, patterns of sexual activity among these young mothers and their sexual partners, additional behavioral and social parameters, or perhaps the unusually intensive nature of our preliminary studies. Therefore the presently proposed investigations will broaden and extend these observations to a larger group of pregnant adolescents and apply the same intensive study techniques to comparison groups including a population of non-pregnant adolescents (sexually active and inexperienced) and a cohort from the same socioeconomic background of older pregnant women and their offspring. Developmental and neurosensory studies are proposed of the infants to establish whether the prevalence of gestational, pre- and perinatal CMV infections is a significant factor in the poor outcome of some adolescent pregnancies. Additionally, it is the aim of these studies to evaluate the source and impact of prevalence-dependent (reactivated or persistent) and incidence-dependent (primary) CMV infections during gestation. In addition to classic virologic and serologic techniques, tests are proposed of samples derived in the course of these studies which it is hoped will eventually lead to new procedures enabling the rapid, inexpensive, and simple identification of CMV infections.